1. Field of Invention
The present invention relates to an electro-optical device and an electronic apparatus using the same. More particularly, the present invention relates to the structure of a pixel of the electro-optical device.
2. Description of Related Art
Currently, electro-optical devices, such as liquid crystal devices, are used as direct viewing type display devices for various apparatuses. Of these electro-optical devices, in an active matrix type liquid crystal device using thin film transistors (TFTs) as a nonlinear element for pixel switching, as shown in FIG. 21, a TFT array substrate 10 and a counter substrate 20 hold liquid crystals as an electro-optical material therebetween. On the TFT array substrate 10 of these substrates mentioned above, there are provided TFTs 30 and pixel electrodes 9a which are each composed of a transparent conductive film, such as an ITO film, and are each electrically connected to a data line 6a via this TFT 30.
Among liquid crystal devices, in a reflective and a transflective liquid crystal device, a method in which a light reflector 8a for reflecting external light incident on the counter substrate 20 to the counter substrate 20 side is formed at a lower layer side of the pixel electrode 9a, and an image is displayed by using external light emitted from the counter substrate 20 side, which is incident on the counter substrate 20 and is then reflected off of the TFT array substrate 10 side, has been widely performed. In addition, by forming a light reflector at the counter substrate 20 side, external light incident on the TFT array substrate 10 side is reflected off of the counter substrate 20 side, so that an image can be displayed by the external light emitted from the TFT array substrate 10 side. However, in the structure described above, since light passes through the TFT array substrate 10, and the areas at which the TFT's 30 are formed do not allow light to pass therethrough, a bright display cannot be advantageously created. Furthermore, the structure in which a light reflector is provided at the opposite side of the array substrate 10 or the counter substrate 20 from the liquid crystal 50 has also been considered, however, in view of the brightness and parallax, the display quality thereof is significantly inferior to that of the internal electrode structure described above.
In either of the reflective or transflective liquid crystal device described above, when light reflected off of the light reflector 8a has a strong directionality, the viewing angle dependence, that is, a phenomenon in which the brightness of an image changes with change in viewing angle or the like, becomes apparent. Accordingly, when a liquid crystal device was manufactured in the past, a photosensitive resin composed of an acrylic resin or the like having a thickness of 800 to 1,500 nm was applied to a surface of a second interlayer insulation film 5a (surface protection film), and this photosensitive resin film was patterned by a photolithographic method so as to selectively leave an irregularity-forming photosensitive resin layer 13 having a predetermined pattern in an area which is at the lower layer side of the light reflector 8a and is overlaid therewith in plan view. Consequently, on the surface of the light reflector 8a formed above the upper layer side of the irregularity-forming photosensitive resin layer 13, an irregular pattern 8g is formed.
As a result, light incident on the counter substrate 20 reflects off the light reflector 8a while being diffused and enters the counter substrate 20, and hence, the viewing angle dependence of an image displayed on the liquid crystal device can be suppressed.
In the case described above, a TFT is described as an example of an active element for pixel switching, and in addition to that, as an active element, a thin-film diode element (TFD) such as a Metal Insulator Metal (MIM) element may also be used.
However, as in the case of a conventional liquid crystal device, in a method for forming the irregular pattern 8a on the surface of the light reflector 8a by using the irregularity-forming photosensitive resin layer 13, since a step of applying a photosensitive resin is additionally required, there has been a problem in that the manufacturing cost is increased. In addition, it is necessary to add a step of selectively leaving the photosensitive resin thus applied by using a photolithographic technique so as to form the irregularity-forming photosensitive resin layer 13, and hence, there has been a problem in that the manufacturing cost is increased.